Mattresses are important constituents of the so-called “sleeping systems” (articles related to sleeping). Mattresses comprise a mattress insert that is usually covered by a liner. A mattress insert is also called a mattress core in the field of the art. In a mattress the role of the mattress insert is to provide optimal weight distribution, adequate load support, and an ergonomic sleep environment. A number of different mattress types have become widely used worldwide. These types vary greatly as far as their manufacturing technology, structural configurations, and technological constructions are concerned.
In the mattress insert according to U.S. Pat. No. 5,604,021 two or three layers of different hardness are laminated on top of one another. The hardness of a given region of the mattress can be adjusted by differently selecting the depth of grooves machined in the mattress insert, as well as the choice of the materials applied for the given layers.
In U.S. Pat. No. 7,000,277 B2 a foam spring mattress (comprising spring-shaped stubs, or in another words, blocks) is disclosed, wherein the foam springs are separated from each another by rectangular blocks also made of foam material. The spring-shaped blocks and the rectangular blocks arranged between them together form a covering surface of even height.
In DE 10 2007 051 232 A1 a mattress formed with foam springs is disclosed, wherein foam springs of different width correspond to different regions of the mattress surface.
In U.S. Pat. No. 4,901,387 a mattress comprising foam blocks is disclosed, wherein the height of the foam blocks may be different at different (e.g. leg, waist, head) regions, but the height is uniform within a given region. Such an arrangement may provide different-height support for different body regions. A similar solution is disclosed in U.S. 2011/0004998 A1, wherein surfaces of different height may be formed, for instance for supporting different body parts, by applying separate foam springs inserted in a sheet. The foam springs are fixed into the sheet adapted for joining the springs.
Foam blocks comprising spring portions and homogeneous portions of different heights and forming a load support surface of uniform height are disclosed in U.S. Pat. No. 7,496,981 B2, according to which a homogeneous mattress material is disposed in a lower-thickness layer above the taller foam blocks and in a higher-thickness layer above the lower foam blocks.
A mattress having a layered configuration, grooves, and blocks of uniform height, is disclosed in U.S. Pat. No. 7,445,839 B2. In FR 2 220 238 a mattress insert provided with diagonal grooves on a part of it is disclosed. A mattress comprising foam blocks having multiple layers of different density and firmness is disclosed in FR 2 539 297 and WO 2013/126972 A2. A common characteristics of known mattress insert arrangements comprising multiple layers having different density and firmness is that the blocks comprising the layers have the same height over the entire load surface of the mattress inserts, or for instance over a continuous region thereof corresponding to a given body region.
In U.S. Pat. No. 4,768,251 a mattress arrangement comprising foam blocks is disclosed wherein foam blocks of different heights and shapes are arranged at different regions of the mattress.
In CN202112704 U, CN202234187 U and U.S. 2011/0041252 A1 spring mattresses are disclosed wherein a spring of greater height is surrounded by springs having lower heights. Arrangements formed with springs have the disadvantage that the springs cannot be arranged with arbitrarily small spacings between them; the manner in which the springs are arranged being determined by the spatial extension of the springs. Thereby, due to the application of springs, the load support surface of such mattress inserts will have surface portions—having a relatively large size with respect to the cross sectional area of the springs—that are not supported either by the taller or by the lower-height springs. This disadvantage cannot be eliminated utilising solutions applying springs.
A common disadvantage of several widely used mattress types is that they are capable of providing sufficient support only within an extremely restricted load range, i.e. their support firmness is not dependent on the load to which the mattress is subjected to. Known mattresses are incapable of following the weight gains and weight losses of the human body, and are also not capable of providing a uniform support force for persons of different weights. Thereby, they are incapable of providing the same level of comfort for users of various weights.
A known mattress arrangement that provides adequate support for a person weighing e.g. 75 kg is incapable of adequately supporting and shape-following the body of a person weighing 100 kg. This problem is not solved even by mattress types comprising a uniform structure but consisting of sections of different firmness (ergonomic zones). Although these mattress types solve the problem of following the shape of the body more accurately, but are not capable of providing a supportive reaction force that conforms to the needs of persons having various body weights.
This problem occurs with all known mattress types, such as mattresses comprising Bonnell springs, foam mattresses, and pocket spring mattresses. Of these mattress types, pocket spring mattresses may have high-level shape-following ability, but resulting from their uniform structure (springs having homogeneous material) they are not capable of responding to different loads with differentiated reaction forces. This disadvantage is especially conspicuous in case of the spring mattress inserts according to CN202112704 U, CN202234187 U and U.S. 2011/0041252 A1 wherein the resistance of the springs can only be adjusted by adjusting a spring constant that is uniform along the entire length of the given spring. The vast majority of known mattress solutions have surface configurations wherein a single surface plane is formed.
Based on the above reasoning it can be concluded that known mattress inserts being spring-type or not, are not capable of following any change in the mass or weight distribution of the user's body, and are also incapable of fulfilling the requirements posed by the fact that users have different builds and weights.
A further problem is posed in relation to known mattresses. Mattresses are articles that are subjected to very heavy use. Consequently, the support capability and capability of even weight distribution of the mattresses gradually deteriorate over the years due to the naturally occurring structural changes and fatigue of their materials. It has to be noted here that the average mattress usage duration and replacement cycle time of households is well over ten years. Taking into account the conditions required for healthy sleep, the changes occurring in a mattress insert due to structural fatigue over the average replacement cycle time, and the mass and shape changes the human body undergoes during that time, it is clearly seen that the disadvantages of known mattresses may appear already in a short period of time. Furthermore, due to the reasons detailed above, a significant deterioration of support and shape following capabilities is inevitable in the long run, which, in addition to uncomfortable sleep, may cause serious health, concentration, and performance problems for the user.
In view of the known solutions, there is a demand for a mattress insert that is capable of providing even body support for persons having various body weights.